ndmpd/tlm/tlm_hardlink.c

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * BSD 3 Clause License
 *
 * Copyright (c) 2007, The Storage Networking Industry Association.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 *  - Neither the name of The Storage Networking Industry Association (SNIA)
 *    nor the names of its contributors may be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include "tlm.h"
#include "tlm_proto.h"

#define HL_DBG_INIT     0x0001
#define HL_DBG_CLEANUP  0x0002
#define HL_DBG_GET  0x0004
#define HL_DBG_ADD  0x0008

static int hardlink_q_dbg = -1;


struct hardlink_q *
hardlink_q_init()
{
    struct hardlink_q *qhead;

    qhead = (struct hardlink_q *)malloc(sizeof (struct hardlink_q));
    if (qhead) {
        SLIST_INIT(qhead);
    }

    if (hardlink_q_dbg & HL_DBG_INIT)
        NDMP_LOG(LOG_DEBUG, "qhead = %p", qhead);

    return (qhead);
}

void
hardlink_q_cleanup(struct hardlink_q *hl_q)
{
    struct hardlink_node *hl;

    if (hardlink_q_dbg & HL_DBG_CLEANUP)
        NDMP_LOG(LOG_DEBUG, "(1): qhead = %p", hl_q);

    if (!hl_q)
        return;

    while (!SLIST_EMPTY(hl_q)) {
        hl = SLIST_FIRST(hl_q);

        if (hardlink_q_dbg & HL_DBG_CLEANUP)
            NDMP_LOG(LOG_DEBUG, "(2): remove node, inode = %lu",
                hl->inode);

        SLIST_REMOVE_HEAD(hl_q, next_hardlink);

        /* remove the temporary file */
        if (hl->is_tmp) {
            if (hl->path) {
                NDMP_LOG(LOG_DEBUG, "(3): remove temp file %s",
                    hl->path);
                if (remove(hl->path)) {
                    NDMP_LOG(LOG_DEBUG,
                        "error removing temp file");
                }
            } else {
                NDMP_LOG(LOG_DEBUG, "no link name, inode = %lu",
                    hl->inode);
            }
        }

        if (hl->path)
            free(hl->path);
        free(hl);
    }

    free(hl_q);
}

/*
 * Return 0 if a list node has the same inode, and initialize offset and path
 * with the information in the list node.
 * Return -1 if no matching node is found.
 */
int
hardlink_q_get(struct hardlink_q *hl_q, unsigned long inode,
    unsigned long long *offset, char **path)
{
    struct hardlink_node *hl;

    if (hardlink_q_dbg & HL_DBG_GET)
        NDMP_LOG(LOG_DEBUG, "(1): qhead = %p, inode = %lu",
            hl_q, inode);

    if (!hl_q)
        return (-1);

    SLIST_FOREACH(hl, hl_q, next_hardlink) {
        if (hardlink_q_dbg & HL_DBG_GET)
            NDMP_LOG(LOG_DEBUG, "(2): checking, inode = %lu",
                hl->inode);

        if (hl->inode != inode)
            continue;

        if (offset)
            *offset = hl->offset;

        if (path)
            *path = hl->path;

        return (0);
    }

    return (-1);
}

/*
 * Add a node to hardlink_q.  Reject a duplicated entry.
 *
 * Return 0 if successful, and -1 if failed.
 */
int
hardlink_q_add(struct hardlink_q *hl_q, unsigned long inode,
    unsigned long long offset, char *path, int is_tmp_file)
{
    struct hardlink_node *hl;

    if (hardlink_q_dbg & HL_DBG_ADD)
        NDMP_LOG(LOG_DEBUG,
            "(1): qhead = %p, inode = %lu, path = %p (%s)",
            hl_q, inode, path, path? path : "(--)");

    if (!hl_q)
        return (-1);

    if (!hardlink_q_get(hl_q, inode, 0, 0)) {
        NDMP_LOG(LOG_DEBUG, "hardlink (inode = %lu) exists in queue %p",
            inode, hl_q);
        return (-1);
    }

    hl = (struct hardlink_node *)malloc(sizeof (struct hardlink_node));
    if (!hl)
        return (-1);

    hl->inode = inode;
    hl->offset = offset;
    hl->is_tmp = is_tmp_file;
    if (path)
        hl->path = strdup(path);
    else
        hl->path = NULL;

    if (hardlink_q_dbg & HL_DBG_ADD)
        NDMP_LOG(LOG_DEBUG,
            "(2): added node, inode = %lu, path = %p (%s)",
            hl->inode, hl->path, hl->path? hl->path : "(--)");

    SLIST_INSERT_HEAD(hl_q, hl, next_hardlink);

    return (0);
}

int
hardlink_q_dump(struct hardlink_q *hl_q)
{
    struct hardlink_node *hl;

    if (!hl_q)
        return (0);

    (void) printf("Dumping hardlink_q, head = %p:\n", (void *) hl_q);

    SLIST_FOREACH(hl, hl_q, next_hardlink)
        (void) printf(
            "\t node = %lu, offset = %llu, path = %s, is_tmp = %d\n",
            hl->inode, hl->offset, hl->path? hl->path : "--",
            hl->is_tmp);

    return (0);
}